Improvement in poweb hammees



F. PRESTON. POWER HAMMER.

110.611,56?. Patented May. 7, 1867.

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IMPROVEMENT 1N" POWER EAMMERS.

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To ALL wHeM AI'r MAY colmena= Be it known thatI, THOMAS F. PRESTON, ofPawtucket, in the county of Providence, and State of Rhode Island, haveinvented a new' and improved Power Hammer; and I do hereby declare thatthe following is a full, clear, and exact description thereof, whichwill enable those skilled in the art to make and use the same, referencebeing had to the accompanying drawings, forming part of thisspecicatiomin 'which-4- Figure 1 is a side elevation of my improvedpower hammer. i `Figure 2 is a front elevation of the same.

Figure 3 is a horizontal sectional view ofthe same, the planejot's'ectionbeing indicated bythe linexzv, iig. 1-

Figure 4 is'a detail sectional view taken on the line y y, iig. 3.

Similar letters of reference ,indicate corresponding parts. .y Theobject of this invention is to construct a power hammer in such a mannerthat thehammer will not ilap about loosely/,but that its motion will beperfectly steady7 and thatenoshock will beconimunicated to the worlt#ing parts above. The invention is chiefly intended as-an improvement onthe hammer of- Thomas Shaw, vpatented February 27, 1866. 3

The improvement consists, first, in the useiof a rod for suspendingthehammam-in placeiof the spring in Shaws hammer. The rod'is providedwvitha' shoulder,.ahove and below which spiral vsprings are arranged, whichwork between `the said shoulder and the respective ends of a. slot in.theupper-fportion et' thehammerl The lower one of these springs iscompressed by the work, while the upper one prevents the violent shockot' the hammer as it is brought down. Theimpcvemeat consists also inmaking the guides, wherein the hammer slides up and down, `in separatepieces, instead of casting them in one piece with the guide-brace, 'asin Shaws hammer. 'lhreby the said guides may be set up or adjusted as4they become worn, while otherwise no accuracy whatever could beobtained.

A is the standard or support, made of cast iron o r other suitablematerial. y' The horizontal shaft B is mountedin suitable boxes arrangedon the said standard, and is provided'with a crank-wheel, C. .By thecrankpin a the connecting-rod D is attached to the wheel C, its lowerend being pivoted to a rod, E, which is attached to the upper end of thehammer F. The said hammer F is provided, as shown' ingfl, with aslotted' upper` extension, the edges of which are provided withguide-rails, b, fitting into grooves Ain the adjustable' guides c. Therod E is within the slot in F provided with a shoulderer projecting ringor pin d, whereby two spiral Sp1-ings, e and f, are pressedrespectivelyagainst the upper and lower enclosure of the slot during themovemcntsof the hammer. a hole in thc hammer. The guides c are lct intothe guide-brace G, and are provided with a lipjon each end to During thedownward stroke of the hammer, the lower end of the rod E is pressedinto prevent their being moved up or down. Two (more oi' less)set-screwsh t'are used for the purpose of holding these guides inplace,and at theproper distance from the hammer, so that thereby theseguides can at all times be adjusted to the rails b on the hammer. In thedrawing only one guide is represented, but in a working machine two haveto bc used, one on either side -of the hammer.

i I claim as new, and desire to secure by Letters Patenty 1. Theconnecting-rods E and D, in combination with the springs e and f,shoulder d, and slotted hammer (orvext'ension of the same) F,substantially as and for the purpose herein shownl and described.

2. The construction and arrangement of the adjustable guide C, .let intothe guide-brace G, and provided xvi'tha lip upon each end fitting overthe upper and lower sides of said guide-brace G', its centre groored toreceive the sliding guidc-rail b n the hammer F, substantially as`hereindescribed and for the purpose specified.

i THOMAS F. PRESTON.

Witnesses:

WILLIAM J. ARNOLD, FRANcIs Foss.

